SHRD: A Scalable Scheme for Hierarchical File Sharing With Rank-Aware Dissemination

SHRD is a new method for securely sharing files in cloud storage systems that need to handle complex hierarchical structures (like in hospitals or government agencies where different people have different access levels). The approach improves on existing methods by reducing computational overhead (the processing work required) through a symmetric key hierarchy that allows one encryption operation to handle multiple files, and by using a rank-aware dissemination tree (a structure that accounts for user access levels) that eliminates redundant re-encryption (the process of converting encrypted data so different users can access it).